The Delta first booster rolls into position through the open door of the Horizontal Processing Facility at Space Launch Complex 2.

The Delta first-stage booster for NASA's Orbiting Carbon Observatory-2 mission, or OCO-2, rolls into position through the open door of the Horizontal Processing Facility at Space Launch Complex 2 on Vandenberg Air Force Base in California.

OCO-2 is scheduled to launch aboard a United Launch Alliance Delta II rocket on July 1, 2014. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere and provide scientists with a better idea of the chemical compound's impacts on climate change. Scientists will analyze this data to improve our understanding of the natural processes and human activities that regulate the abundance and distribution of this important atmospheric gas. To learn more about OCO-2, visit http://oco.jpl.nasa.gov. Photo credit: NASA/D. Liberotti, 30th Space Wing, VAFB